Updated cesium integration (markdown)

cesium-integration.md

@@ -6,6 +6,9 @@ Idea: A vector on the 2D map displays the view point and the view direction:
 
 See example with OpenLayers 2 and Google Earth plugin: http://plan.epfl.ch/?lang=en, click in the right menu on 3d. 2D and 3D are snychronized. 
 
+Question: How do get the same control feeling when manipulating the Ol3 view / the Cesium view?
+Uses cases are: stacked views or separated views like for EPFL.
+
 ## Smooth transition between 2d and 3d
 Idea: A la google map, share the bottom line and tilt. Forward and Backward.
 
@@ -15,6 +18,10 @@ Ongoing work:
 * 1. POC: http://bl.ocks.org/tonio/raw/9759909/
 * To be developed further: http://bl.ocks.org/gberaudo/raw/51f050326d91d4e9c09a/1b55ad64a1f3de2dcba5673ecb52f976104a4592/#
 
+Remarks:
+* all directions must be handled (not just NS and EW);
+* all tilted situations must be handled (starting from an arbitrary tilted angle).
+
 ## Sync raster data sources
 Idea: If a user adds a WMS/TMS/WMTS layer to ol3.js map it should also be added to the cesium globe.
 
@@ -58,7 +65,7 @@ This integration is developed in an open source layer built ontop of ol3js as ol
  * Compute from scratch a new state from the new context?
 * Save computing resources
  * disable rendering of the underlying map or globe if it's hidden by the overlayed one
- * still preseve context synchronization
+ * still preserve context synchronization
 * Smooth transition needs to know the elevation of the destination point of the camera
  * cesium provides an asynchronous method
  * cesium provides in a dev branch a specific method. TDB: WHERE?